Peter G. McGovern, MD, director, Division of Reproductive Endocrinology and Infertility, University of Medicine and Dentistry of New Jersey, Newark; medical director of University Reproductive Associates, Montclair, NJ

Fertility Specialist

What Are Intramuscular Injections?

What are intramuscular injections, and how are they used in fertility treatment?

If you’re undergoing fertility treatments, consider yourself lucky. In the early days of assisted reproduction, most of the medications had to be delivered into the butt or thigh muscles in what’s known as intramuscular (IM) injections. Today the vast majority of fertility drugs can be delivered just below the skin ( subcutaneously), with much smaller needles and a lot less discomfort.

If you do end up having IM shots, know that they’re a little awkward to self-administer, so you may have to call upon your partner or a friend to lend a helping hand. But despite the bigger needle and uncomfortable angles, IM injections do have their advantages. For one, the absorption levels are more predictable, because muscle tissue is generally more uniform than fat. If you undergo egg retrieval, you may be given a dose of intramuscular progesterone to help support the lining of the uterus. The good news if you’re scared of needles: The progesterone can also be taken orally (in pill form) or vaginally (in a suppository).